In many applications an electronic chip is provided to perform one or more functions, including the control of current provided to an external device, or load. In order to ensure proper powering of the external device, or load, the provided current should be measured. For example, Power over Ethernet (PoE), in accordance with both IEEE 802.3af-2003 and IEEE 802.3at-2009, each published by the Institute of Electrical and Electronics Engineers, Inc., New York, the entire contents of each of which is incorporated herein by reference, defines delivery of power over a set of 2 twisted wire pairs without disturbing data communication. The aforementioned standards particularly provide for a power sourcing equipment (PSE) and one or more powered devices (PD). In a first stage of operation, the PSE is arranged to output to each PD a class current, typically ranging from 0-50 mA, in order to determine the class of the PD. In the operating stage of operation, the PSE is arranged to output an operating current, typically ranging from 350 mA-1 A. In both stages, the current output by the PSE should be measured in order to determine if there is enough power for all of the PDs.
Unfortunately, analog to digital converters (ADCs) capable of properly converting such a wide range of currents add additional costs. There is thus a long felt need for an arrangement allowing for the conversion of a wide range of input currents by a standard ADC.